1. Field of the Invention
The present invention relates to a digital-to-analog converter (hereinafter referred to as a D/A converter), and particularly, to a D/A converter for providing an output voltage Vout=Vin.multidot.X/2" in response to an input voltage Vin and an n-bit digital input X.
2. Description of the Related Art
Recently, digital technology is rapidly improved, and D/A converters are used in various fields. It is necessary, for large scale integrated circuits (LSIs), to minimize an area occupied by a D/A converter. To reduce the area, the D/A converter for providing an output voltage Vout=Vin.multidot.X/2" in response to the input voltage Vin and n-bit digital input X must employ small field-effect transistors (FETs) served as switching elements.
The problems of the prior art will be explained later with reference to the accompanying drawing and some equations.